Handout by Mrs. Moore & Supplement PowerPoint by Mrs. Peachee Ceramic Glazes Handout by Mrs. Moore & Supplement PowerPoint by Mrs. Peachee

BEFORE YOU EVEN CONSIDER GLAZING… Is your piece dry? Do you have a design? Did you get permission? Did you sand your piece for any rough patches? Did you clean your piece with a damp cloth?

General information Make up of Glazes: Come powder or liquid Glass Silica Pigment (mineral color) Come powder or liquid

Slip Glazes Different colored slips (underglazes) Can be scratched using (sgraffito technique) Can be placed in relief cut impressions (Mashima technique)

General continued Liquid Glazes: Brush Can settle if left to sit Shake well Open and stir with the handle of brush (clean off before use) Dry glazes can have water added to bring back to life Brush should be soft bristled. Always clean your brush thoroughly when finished dry bristle up. Detail work requires glaze that will not flow

Glazes can be poured or dipped for faster application melt at specific temperatures. Becomes molten and seals pores Clay molecules lose hydrogen bonds and shrink porous nature of clay. Clay is still porous without the use of glazes. While porous pieces can not hold water.

Green ware & bisque ware Clay that has not been fired. Often must be fired before glazed Some underglazes may be applied prior to firing. Firing prior to under glazing can be important for adding strength. Bisque Ware After kiln fired (usually cone 04) Glazed pieces may be placed on stilts if glazed on bottom. Can you spot the bisque Ware?

Safety Hazards LEAD! Silica Poisonous substance Can NOT be used for food containers. Can cause brain damage Silica In powder form you must wear a mask. Sticks to your lungs & cause breathing problems. WATCH YOUR LABELS K-6 Lead free NON-TOXIC Conforms to ASTM D-4236 LEAD-FREE   CAUTIONS REQUIRED Restricted From Use K-6 LEAD-FREE Conforms to ASTM D-4236/LHAMA 7-12 Lead free

Application Glazes – consistency of heavy cream Rough textures Flows off brush Apply 3 even coats (2nd firing approximately 1850 degrees for 8 hours-Cone 06) Rough textures Water down and apply additional coats Do not backstroke 1/16th to 1/8th inch thick (thumbnail check) Remove excess glaze from bottom with damp sponge.

Types of glazes Underglazes “Matte” finish Used for details Do not flow Use a soft brush to apply

Types of Glazes TRANSPARENT Clear like water “high Gloss” Used over an underglaze often Food safe Seals pores

Colored glaze Transparent Translucent Opaque Can see through layers Can layer colors Translucent Can see partially through layers Opaque Can not see through layers Blocks colors below

Art Glaze Contains particles that break up while firing Specific firing setting needed More prone to running Unpredictable